In U.S. Pat. Nos. 6,522,042, 6,983,529 and 7,088,024, it is described that anchors for stator housings are formed in the housing or a flux ring, magnets are placed in the housing or flux ring such as between the anchors, and a plastic material is overmolded that fills around the anchors to secure the magnets to the flux ring or housing. The entire disclosures of U.S. Pat. Nos. 6,522,042, 7,088,024 and 6,983,529 are incorporated by reference herein.
In a known process, uniform thickness, sintered NdFeB magnets are made by a preliminary shaping process, followed by precise OR and IR grinding to obtain tight tolerances and a constant thickness across the arc of the magnet. Such preliminary shaping processes are hole sawing or wire EDM. This is typically done starting from solid blocks of magnet material. Another method is to press discrete magnets to their near-net shape.